The purpose of this study is to report a case which showed the symptoms of brachial plexus palsy after resection of outer end of the clavicle. A 42 years-old, male, had a traumatism in a traffic accident in October 2002. At the beginning, he underwent medical treatment to his head externally caused by the injury. He complained of right shoulder pain and numbness of his right shoulder in the upper limbs after the resection of the outer end of the clavicle. Then, he consulted our clinic. At first, the outer end of the clavicle was dislocated to upper back direction. The range of motion of his right shoulder was slightly limited. Atrophy of the deltoid muscle existed, and the muscle power of deltoid was weak. Numbness existed in the right axillary nerve area and the right forearm. The electromyogram suggested radiculopathy of C5 root. We performed a Dewar method operation to reduce the acromioclavicular joint. In our operation, the nerves of the brachial plexus were distracted under the coracoid process. The nerves were loosened after the reduction of the clavicle. After the operation, the symptoms that were related to the nerves recovered. We performed a Dewar method operation because the symptom appeared to be caused by a disorder of the coracoclavicule mechanism. At the operation, the neurovascular bundle was pulled between the clavicle and the coracoid process. Many cases of the dislocation of the acromioclavicular joint do not present a nerve symptom. We discussed the reasons why the symptoms about the nerves presented themselves in this case. We considered the reasons why in this case brachial plexus palsy, the existed a dysfunction of the scapulothoracic joint before the resection of the outer end of clavicle.
